1. Field of the Invention
The present invention relates, in general, to light illuminated display devices, such as display boards, and lighting devices, such as lamps, and, more particularly, to an improvement in such devices to accomplish a desired lighting effect with illumination light using a light refraction and reflection effect within transparent acrylic plastic plates.
2. Description of the Prior Art
As well known to those skilled in the art, a conventional light illuminated display board is designed to accomplish a desired illumination effect by an edge lighting-type structure. This edge lighting-type structure comprises a plurality of transparent or translucent plastic plates, with the four edge surfaces of each plastic plate being flat and a light source being arranged along each edge of each plate for emitting light to the displaying surface of the display board. In such a conventional edge lighting-type display board, the brightness of the displaying surface of the board is determined only by the arrangement and light intensity of the light sources arranged along the four edges of the plastic plates. Therefore, it is almost impossible for the conventional edge lighting-type display boards to accomplish a desired level of illumination and brightness, a desired alteration of both the illumination and brightness or a desired cubic effect for advertisements or notices displayed on the board.
U.S. Pat. No. 5,124,890, allowed to the inventor of this invention, discloses "Display Board Illuminated by Refracted Light". As disclosed in the above U.S. patent document, this display board comprises a plurality of transparent acrylic plastic plates, in which desired light is received from the light emerging edges of the plastic plates to the light receiving edges of the plates using a light refraction and reflection effect within the transparent acrylic plastic plates. The advertisements or notices of the display board, formed by letters, figures, symbols and/or a combination of them, are illuminated by refracted light. In the above display board, the four edges of each plastic plate are formed to be flat, thus individually having a flat surface.
In the above display board, a variety of lamps, such as light bulbs, may be preferably used as a light source illuminating the displaying surface of the board. The above bulbs are arranged within a closed and narrow space formed in the board frame, and so the bulbs may overheat the plastic plates. When high wattage bulbs are used in the display board in an effort to increase the light intensity of the bulbs and to accomplish a desired brightness of the displaying surface, the bulbs undesirably and exceedingly overheat both the acrylic plastic plates and the color sheets attached to the light receiving edges of the plastic plates. In such a case, the plastic plates and the color sheets may be thermally damaged to be discolored, deformed and/or distorted, thus causing a deterioration in both the color alteration and the light intensity of incident light in the case of using the display board for a lengthy period of time. The above display board thus may be remarkably reduced in its advertising effect or its lighting effect.
In a brief description, the conventional light illuminated display boards, fabricated with transparent acrylic plastic plates, are designed to receive light from the light emerging edges having flat surfaces to the light receiving edges having flat surfaces, thus failing to accomplish a desired lighting intensity or a desired brightness of the displaying surface particularly in day light. Another problem experienced in the conventional light illuminated display boards resides in that they may be thermally damaged to be discolored, distorted or deformed due to the lighting bulbs installed within the display boards. It is thus necessary to provide a light illuminated display board, which allows the advertisements or the notices of the displaying surface to be effectively illuminated by light to be clearly and prominently displayed on the surface in addition to accomplishment of a clear and prominent advertising effect and being effectively usable for a lengthy period of time.
On the other hand, most conventional indoor electric lamps, such as floor lamps and table lamps, have cylindrical or frusto-conical shades, typically made of light transmitting fabrics, such as natural fabrics and synthetic fabrics, or made of other sheet materials. In such indoor electric lamps, the shades intercept direct light from bulbs while accomplishing a desired indirect lighting effect.
Such conventional shades are merely designed to accomplish an indirect lighting effect of the indoor lamps. Of course, some shades, with the external surfaces of the shades printed with letters, figures, color designs, color patterns and/or a combination of them, have been proposed and used.